Automatic device for optimised muscular stimulation

ABSTRACT

An automatic device for optimized muscular stimulation, which provides periodical contractions with constant frequency of one or more muscles of a user, includes a central electronic unit ( 1 ), connected to a memory unit ( 2 ), to one or more muscular electrical activity detectors ( 4 ), each one applied on a corresponding muscle of the user, and to muscular stimulation elements ( 5 ) actuated by the central unit ( 1 ). The central unit ( 1 ) manages and controls the automatic device, processes data coming from the detectors ( 4 ) in such a way to determine, within a range included between a lower limit frequency and an upper limit frequency, an optimum frequency of the periodical contractions in correspondence of which the sum of the amplitude of the signals provided by the detectors ( 4 ) from the corresponding muscles of the user as a response to the stimulation is the maximum one. The central unit ( 1 ) sets the muscular stimulation elements in such a way to produce periodical contractions of the muscle to be stimulated at the determined optimum frequency.

[0001] The present invention relates to an automatic device foroptimised mechanical muscular stimulation and/or stressing.

[0002] More specifically, the invention concerns a device of the abovekind, the stimulation of which, preferably mechanically produced,provides constant frequency periodical contractions of a muscle of auser, providing the preliminary detection of the frequencies of theperiodical contractions corresponding to the best electromyographycalresponse for the muscle to be stimulated, and a following stimulation ofthe same muscle at the optimum frequency sensed, the device being highlyreliable and efficient.

[0003] It is known that when a muscle is stimulated by application ofmechanical vibrations, it contracts in a reflex way very similarly towhat happens when the muscle is operated by voluntary contractions, e.g.during the execution of physical works.

[0004] Particularly, varying the frequency of the mechanical vibrations,it is possible to make selectively working fast or slow muscular fibres.

[0005] Recently, many mechanical devices for the muscular stimulationhave been developed, such as a board, for the leg muscles, or avibrator, for the arm muscles.

[0006] Said devices are useful for training of agonistic level athletes,since they allow to obtain the same results of the standard physicalexercises within the gymnasium in a shorter time, to obtain a goodmuscular tono by few application minutes at home, and for physicaltherapy uses aimed to the maintenance of the muscular tone or to thefunctional recover of the muscles, for example during or afterimmobilisation periods due to fractures or surgical intervention.

[0007] However, present mechanical muscular stimulation devices has somedrawbacks.

[0008] Main drawback is represented by the fact that the mechanicalvibration frequency, that can be manually set, is not optimised eitherfor the specific fibres of a determined muscle of the specific user andfor the whole body.

[0009] In fact, specific fibres of any muscle of any single user has aresponse to the micro-vibrations variable while varying the frequency ofthe applied vibration. Particularly, it can be individuated a frequencyrange, which can be defined “activity range”, within which specificfibres of the particular muscle respond to the stimulations and, withinsaid range, it can be determined an optimum mechanical frequency incorrespondence of which said response is the maximum one. In case theset frequency is different with respect to the optimum one, the work ofthe interested muscle is not efficient for its toning up and, in casefrequency set is not included within the activity range, muscular workis completely null. In some cases, the wrong set of the vibrationfrequency could even produce harmful results.

[0010] Similar drawbacks are present in electrical muscle stimulationdevices, the frequency off the electrical signal of which, applied tothe specific muscle, is not optimised.

[0011] In this situation, it is suggested the solution according to thepresent invention, allowing to solve all the above mentioned drawbacks.

[0012] Therefor, the object of the present invention is that ofproviding a preferably mechanical device, which is reliable, efficientand simple to be used, for the muscular stimulation, able to determinein an automatic way the optimum periodic stimulated contractionfrequency for which the specific fibres of the particular interestedmuscle have the maximum, not only muscular, but also generally speakingbiological, response.

[0013] Still an object of the present invention is that of providingsuch a device for the muscular electro-stimulation, able toautomatically determine the optimum frequency of the electronic signalto be applied at the particular interested muscle in such a way tostimulate periodic contractions with an optimum frequency.

[0014] It is therefore specific object of the present invention anautomatic device for optimised muscular stimulation, the stimulationproviding periodical contractions with constant frequency of one or moremuscles of a user, the device comprising a central electronic unit,connected to a memory unit, to one or more muscular electrical activitydetectors, each one applied on a corresponding muscle of the user to besubjected to stimulation, and to muscular stimulation means actuated bythe central unit, the central unit managing and controlling theautomatic device, processing the data coming from the detectors in sucha way to determine, within a range included between a lower limitfrequency and an upper limit frequency, an optimum frequency of theperiodical contractions in correspondence of which the sum of theamplitude of the signals provided by the detectors from thecorresponding muscles of the user as a response to the stimulation isthe maximum one, the central unit setting the muscular stimulation meansin such a way to produce periodical contractions of the muscle to bestimulated at the determined optimum frequency.

[0015] Preferably, according to the invention, the lower limit frequencyis 1 Hz and/or the upper limit frequency is 1000 Hz.

[0016] Still preferably, according to the invention, muscularstimulation means are mechanical means.

[0017] Always according to the invention, the mechanical means canprovide a support structure on which a jumpy board is placed, on whichthe user is placed, comprising a metallic plate at which at least engineis coupled having an eccentric mass, able to produce the vibration ofthe plate, piloted by an electronic device comprising an inverterconnected to a potentiometer adjusting the vibration frequency, thecentral unit setting said vibration frequency.

[0018] Furthermore according to the invention, the mechanical means canprovide a support structure on which a tilting board is placed.

[0019] Still according to the invention, the muscular stimulation meanscan be electrical means.

[0020] Further, according to the invention, the detector can comprisemedical electrodes, amplified in situ, an insulation amplifier and asignal converter providing at the outlet a digital signal read by thecentral unit.

[0021] Always according to the invention, each one of said one or moredetectors can comprise medical electrodes, amplified in situ, aninsulation amplifier and a signal converter providing at the outlet adigital signal read by the central unit.

[0022] Furthermore, according to the invention, the central unit canfollow a determination method of the optimum frequency comprising thephases of:

[0023] application of said one or more detectors to the correspondingmuscles to be stimulated;

[0024] repetition for N times, preferably eight times, of a dataacquisition phase during which the central unit actuates the stimulationmeans in such a way to produce periodical contractions of the musclewith a constant frequency for a Δt time, preferably between 5 and 10seconds, with a progressively growing frequency, from a repetition tothe following one and included between the lower limit frequency and theupper limit frequency, processing, for each repetition, the average ofthe amplitude of signals coming from the detectors and memorising thesame within the memory unit along with the value of the correspondingfrequency; and

[0025] determination of the maximum sum of the average of the amplitudeof signals detected by said detectors, wherein the central unitdetermines, between those memorised, the sum of the averages at the samefrequency having the maximum value, individuating the optimum frequency.

[0026] Still according to the invention, consecutive repetitionfrequencies can have each other a constant difference.

[0027] Furthermore, according to the invention, the consecutiverepetition frequencies can have a difference variable and increasing asa function of the absolute value of the frequency of the precedingrepetition.

[0028] Still according to the invention, the central unit can perform adetermination method of the optimum frequency, comprising the phases of:

[0029] application of said one or more detectors to the correspondingmuscles to be stimulated;

[0030] iteration for M times, preferably two times, of cycles of anumber N_(i) of repetitions, wherein i is the i-th repetition, of dataacquisition phases during which the central unit actuates thestimulation means in such a way to produce periodical contractions ofthe muscles with a constant frequency for a Δt time, preferably between5 and 10 seconds, with a progressively growing frequency, from arepetition to the following one and included between the lower limitfrequency and the upper limit frequency, frequencies of consecutiverepetitions having each other a constant difference Δf_(i), the centralunit processing, for each repetition, the average of th amplitude ofsignals coming from the detectors and memorising it within the memoryunit along with the value of the corresponding frequency, the centralunit determining for each iteration i the maximum sum of the average ofthe amplitudes of the signals detected and individuating thecorresponding best frequency for each iteration i, following the firstone, the range between the first lower frequency and the second upperfrequency comprising the best frequency individuated at the precedingiteration, for each iteration i, following the first one, the constantdifference Δf_(i) between the consecutive repetition frequencies beinglower than the difference Δf_(i-1) of the preceding iteration(Δf_(i)<Δf_(i-1)); and

[0031] determination of the optimum frequency at the end of the M-thiteration, wherein the best frequency individuated at the M-th iterationis memorised as the optimum frequency.

[0032] Preferably, according to the invention, for the first iteration,the first lower frequency coincides with the lower limit frequencyand/or the second upper frequency, with the upper limit frequency.

[0033] Still preferably according to the invention, for each iteration ifollowing to the first one, the range between the first lower frequencyand the second upper frequency comprises the best frequency individuatedat the preceding iteration as intermediate frequency.

[0034] Furthermore, according to the invention, the automatic device canalso comprise an inlet/outlet interface, preferably comprising adisplay.

[0035] Always according to the invention, the central unit can visualiseon the display signals detected by detectors and the value of theoptimum frequency individuated.

[0036] Still according to the invention, the device can provide, by theinterface, the manual setting selection of the periodical contractionsof the muscle.

[0037] Furthermore, according to the invention, the interface can beprovided with reading and/writing devices for memory movable supports.

[0038] The present invention will be now described, for illustrative butnot limitative purposes, according to its preferred embodiments, withparticular reference to the figures of the enclosed drawings, wherein:

[0039]FIG. 1 shows a block diagram of the preferred embodiment of thedevice according to the invention;

[0040]FIG. 2 shows the time run of the signal detected by the device ofFIG. 1, applied to the lateral crureus muscle; and

[0041]FIG. 3 shows the time run of the signal detected by the device ofFIG. 1, applied to the front tibialis muscle.

[0042] In the following explicit reference will be made for illustrativebut not limitative purposes to an embodiment of the device according tothe invention the stimulation means of which are mechanical means.However, it must be noted that other embodiments of the device accordingto the present invention can provide that the muscular stimulation meansare electrical or electromechanical means, always remaining within thescope of the present invention.

[0043] Making reference to FIG. 1, it can be noted that the preferredembodiment of the device according to the invention comprises a centralelectronic unit 1, connected to a memory unit 2 and to an inlet/outletinterface 3. Central unit 1 is also connected to a detector 4 ofmuscular electric activity and to mechanical stimulation mechanicalmeans 5.

[0044] Detector 4 comprises medical electrodes 6, amplified in situ, aninsulation amplifier and a signal converter providing at the outlet adigital signal read by the central unit 1.

[0045] Mechanical means 5 provides, in the preferred embodiment, for thestimulation of the leg muscles, a support structure on which a jumpyboard is placed, on which the used is placed, comprising a metallicplate, rest on rubber shims allowing its vibration. Two engines arecoupled with the plate, having eccentric masses, able to produce thevibration of the plate, piloted by an electronic device comprising aninverter connected to a potentiometer adjusting the vibration frequency,the central unit setting said vibration frequency. Particularly, centralunit 1 sets said vibration frequency. Support structure can provide arod or handle for the user.

[0046] As it known, the vibration mechanical frequency of the mechanicalmeans 5 of the stimulation coincides with the frequency of theperiodical contractions of the muscle induced by the stimulation.

[0047] Central unit 1 manages and controls all the components of theautomatic device, processing data coming form detector 4 in such a wayto determine within said range included between a lower limit frequency,preferably equal to 1 Hz, and an upper limit frequency, preferably 1000Hz, the optimum vibration frequency of the tilting board incorrespondence of which the specific muscle has the maximum response tothe stimulation and consequently setting vibration frequency of themechanical means 5.

[0048] In a first embodiment of the device according to the invention,it is provided a method for the determination of the optimum frequencycomprising the phases of:

[0049] application, in a conventional way, of the medical electrodes 6of the detector 4 to the muscles to be stimulated;

[0050] repetition for N times, N being preferably eight times, of a dataacquisition phase during which the central unit 1 actuates the vibrationwith a constant frequency of the mechanical means 5 for a Δt time, Δtbeing preferably between 5 and 10 seconds, with a progressively growingvibration frequency, from a repetition to the following one and includedbetween the lower limit frequency and the upper limit frequency,processing, for each repetition, the average of the amplitude of signalscoming from detector 4 and memorising the same within the memory unit 2along with the value of the corresponding vibration frequency;

[0051] determination of the maximum electrical response for which thecentral unit 1 determines among those memorised, the average having amaximum value, consequently individuating the optimum vibrationfrequency, for which the specific muscle has the maximum response.

[0052] Preferably, frequencies of consecutive repetitions during thedata acquisition has a constant difference each other; however, it canbe provided also a variable and increasing difference in function of theabsolute value of the frequency of the preceding repetition.

[0053] Once determined the optimum frequency, it can be started themuscular stimulation phase, during which the central unit 1 activatesvibration of mechanical means 5 with said optimum frequency for a timeestablished before or selectable by the user by interface 3.

[0054] For exemplificative purposes, FIGS. 2 and 3 show the time run ofsignal detected by detector 4, during the execution of the describedmethod for the individuation of the optimum frequency, during whichmedical electrodes are respectively applied to the lateral crureusmuscle and to the front tibialis muscle of an user. Particularly, numberof repetitions provided is 6 (N=6) and duration of the constantvibration frequency of the mechanical means 5 is 10 seconds (Δt=10).Vibration frequencies of the six repetitions are 22.5 Hz, 25 Hz, 27.5Hz, 30 Hz, 32.5 Hz and 35 Hz, respectively.

[0055] It is evident from the above figures that optimum frequency(frequency at which average of amplitude has maximum value) for thelateral muscle is the fourth one, i.e. 30 Hz, while for the fronttibialis muscle is the third one, i.e. 27.5 Hz.

[0056] Particularly, lower limit frequency and upper limit frequencycould be variable in function of the specific fibres of the particularmuscle to be stimulated, and settable by the interface 3.

[0057] A second preferred embodiment of the device according to theinvention provides that the method for the individuation of the optimumfrequency, comprising the following phases:

[0058] application in a conventional way of the medical electrodes 6 ofthe detector 5 to the muscles to be stimulated;

[0059] iteration for M times, M being preferably two times, of cycles ofa number N_(i) of repetitions, wherein i is the i-th repetition, of dataacquisition phases during which the central unit 1 actuates the constantfrequency vibration of the mechanical means 5 for a time Δt, Δt beingpreferably equal to 10 seconds, with a progressively growing frequency,from a repetition to the following one, and included between the lowerlimit frequency and the upper limit frequency, frequencies ofconsecutive repetitions having each other a constant difference Δf_(i),where preferably, for the first iteration, first lower frequencycoincides with the lower limit frequency and/or the second upperfrequency coincides with the upper limit frequency, central unit 1processing, for each iteration i the average of the amplitude of thesignal coming from the detector 4 and memorises the same within thememory unit 2 along with the value of the corresponding vibrationfrequency, the central unit 1 determining for each iteration i theaverage with the maximum value and individuating the corresponding bestfrequency for each iteration i, following the first one, the rangebetween the first lower frequency and the second upper frequencycomprising the best frequency individuated at the preceding iteration,for each iteration i, following the first one, the constant differenceΔf_(i) between the consecutive repetition frequencies being lower thanthe difference Δf_(i-1) of the preceding iteration (Δf_(i)<Δf_(i-1));and

[0060] determination of the optimum frequency at the end of the M-thiteration, wherein the best frequency individuated at the M-th iterationis memorised with the optimum frequency for which the maximum responsehas the best response.

[0061] In other words, method described in the above determines optimumfrequency individuating, by a progressively better resolution, thevibration frequency for which the specific muscle has the maximumresponse. Said method is faster with the cost of a slightly higherprocessing load.

[0062] Preferred embodiments of the device according to the inventionprovide visualisation by the interface 3 that can comprise a display forsignal detected by detector 4 and of the value of the optimum frequencyindividuated.

[0063] Other preferred embodiments can provide that the user can selectmanual setting of the vibration frequency by interface 3.

[0064] Further preferred embodiments can provide that values of optimumfrequencies corresponding to the various muscles of a same user arememorised on memory movable supports, such as cards of magnetic and/oroptical discs, by interface 3, to be then read by interface, avoidingfurther executions of the method for the determination of the optimumfrequency. Eventually, optimum frequencies corresponding to an user canbe memorised within memory unit 2 and recalled by association, andinsertion by interface 3, of an identification code of the user.

[0065] Other embodiments can provide that muscular stimulationmechanical means provide a oscillating, rather than jumpy, board, orvibrating means.

[0066] Still, further preferred embodiment can provide more than onemuscular electrical activity detector, each one applied to one muscle ofthe user, to stimulate different muscles at the same time. For example,different muscles of a leg can be stimulated inducing contractions atthe frequency for which the whole of the responses from the muscles onwhich are applied the detectors is bigger. In this case, interface 3 canvisualise on display all the signals detected by the detector.

[0067] Said embodiments can be used for diagnostic uses. For example,detectors can be applied on homologous muscles of the two upper limbs orof the two lower limbs. During the execution of the method for thedetermination of the optimum frequency, in case that one of the twolimbs has been subjected to surgical intervention, and thus a mechanicalinsult has been made on the biological tissue (for example musclesand/or chorda and/or capsule and/or ligaments), response detected forthe limb subjected to a surgical intervention is different with respectto the laudable one. Amount of the response difference of the two limbsindicates the amount of the difference of response of propioceptors ad,thus, amount of damage received from the person at the limb subjected tosurgical intervention.

[0068] The present invention has been described for illustrative but notlimitative purposes, according to its preferred embodiments, but it isto be understood that modifications and/or changes can be introduced bythose skilled in the art without departing from the relevant scope asdefined in the enclosed claims.

1. Method for optimally mechanically stimulating one or more musclesthrough mechanical means (5), one or more muscular electrical activitydetectors (4) being applied on a corresponding muscle to be subjected tostimulation, comprising the following steps: preliminarily determining,within a range included between a lower limit limit frequency and anupper limit frequency, an optimum frequency of muscular periodicalcontractions, due to corresponding periodical mechanical stimulations bythe mechanical means (5), in correspondence of which the sum of theamplitude of the signals provided by the detectors (4) from thecorresponding stimulated muscles as a response to the stimulation is themaximum one, producing periodical contractions of the muscles throughthe mechanical means (5) at the preliminarily determined optimumfrequency.
 2. Method according to claim 1, characterised in that thelower limit frequency is 1 Hz.
 3. Method according to claim 1 or 2,characterised in that the upper limit frequency is 1000 Hz.
 4. Methodaccording to any one of the claims from 1 to 3, characterised in thatthe determination step of the optimum frequency comprises the phases of:repetition for N times of a data acquisition phase during which thestimulation mechanical means (5) are actuated in such a way to produceperiodical contractions of the muscle with a constant frequency for a Δttime, with a progressively growing frequency, from a repetition to thefollowing one and included between the lower limit frequency and theupper limit frequency, processing, for each repetition, the average ofthe amplitude of signals coming from the detectors (4) and memorisingthe same along with the value of the corresponding frequency; anddetermination of the maximum sum of the average of the amplitude ofsignals detected by said detectors (4), wherein it is determined,between those memorised, the sum of the averages at the same frequencyhaving the maximum value, individuating the optimum frequency.
 5. Methodaccording to claim 4, characterised in that N is equal to eight. 6.Method according to claim 4 or 5, characterised in that Δt is equal to 5seconds.
 7. Method according to claim 4 or 5, characterised in that Δtis equal to 10 seconds.
 8. Method according to one of the claims from 4to 7, characterised in that consecutive repetition frequencies have aconstant difference each other.
 9. Method according to one of the claimsfrom 4 to 7, characterised in that the consecutive repetitionfrequencies have a difference variable and increasing as a function ofthe absolute value of the frequency of the preceding repetition. 10.Method according to any one of the claims from 1 to 3, characterised inthat the determination step of the optimum frequency comprises thephases of: iteration for M times of cycles of a number N_(I) ofrepetitions, wherein i is the i-th repetition, of data acquisitionphases during which the stimulation mechanical means (5) are actuated insuch a way to produce periodical contractions of the muscles with aconstant frequency for a Δt time, with a progressively growingfrequency, from a repetition to the following one and included betweenthe lower limit frequency and the upper limit frequency, frequencies ofconsecutive repetitions having each other a constant difference Δf_(i),processing, for each repetition, the average of th amplitude of signalscoming from the detectors (4) and memorising it along with the value ofthe corresponding frequency, determining for each iteration i themaximum sum of the average of the amplitudes of the signals detected andindividuating the corresponding best frequency for each iteration i,following the first one, the range between the first lower frequency andthe second upper frequency comprising the best frequency individuated atthe preceding iteration, for each iteration i, following the first one,the constant difference Δf_(i) between the consecutive repetitionfrequencies being lower than the difference Δf_(i-1) of the precedingiteration (Δf_(i)<Δf_(i-1)); and determination of the optimum frequencyat the end of the M-th iteration, wherein the best frequencyindividuated at the M-th iteration is memorised as the optimumfrequency.
 11. Method according to claim 10, characterised in that M isequal to two.
 12. Method according to claim 10 or 11, characterised inthat Δt is equal to 5 seconds.
 13. Method according to claim 10 or 11,characterised in that Δt is equal to 10 seconds.
 14. Method according toone of the claims from 10 to 13, characterised in that for the firstiteration, the first lower frequency coincides with the lower limitfrequency and/or the second upper frequency, with the upper limitfrequency.
 15. Method according to one of the claims from 10 to 14,characterised in that for each iteration i following to the first one,the range between the first lower frequency and the second upperfrequency comprises the best frequency individuated at the precedingiteration as intermediate frequency.
 16. Automatic device for optimisedmechanical muscular stimulation, the stimulation providing periodicalcontractions with constant frequency of one or more muscles of a user,the device comprising a central electronic unit (1), connected to amemory unit (2), to one or more detectors (4), each one applied on acorresponding muscle of the user to be subjected to stimulation, and tomuscular stimulation means (5) actuated by the central unit (1), thecentral unit (1) managing and controlling the automatic device andprocessing the data coming from the detectors (4), characterised in thatthe detectors (4) are muscular electrical activity detectors (4), inthat the muscular stimulation means (5) are mechanical means and in thatthe central unit (1) performs the steps of the method according to anyone of the claims from 1 to
 15. 17. Automatic device according to claim16, characterised in that mechanical means (5) provide a supportstructure on which a jumpy board is placed, on which the user is placed,comprising a metallic plate at which at least engine is coupled havingan eccentric mass, able to produce the vibration of the plate, pilotedby an electronic device comprising an inverter connected to apotentiometer adjusting the vibration frequency, the central unit (1)setting said vibration frequency.
 18. Automatic device according toclaim 16, characterised in that mechanical means (5) provide a supportstructure on which a tilting board is placed.
 19. Automatic deviceaccording to one of the claims from 16 to 18, characterised in that theeach one of said one or more detectors (4) comprises medical electrodes(6), amplified in situ, an insulation amplifier and a signal converterproviding at an output a digital signal read by the central unit (1).20. Automatic device according to one of the claims from 16 to 19,characterised in that the automatic device also comprises aninput/output interface (3).
 21. Automatic device according to claim 20,characterised in that the interface (3) comprises a display. 22.Automatic device according to claim 21, characterised in that thecentral unit (1) visualises on the display signals detected by detectors(4) and the value of the optimum frequency individuated.
 23. Automaticdevice according to any one of the preceding claims from 20 to 22,characterised in that provides, by the interface, the manual settingselection of the periodical contractions of the muscle.
 24. Automaticdevice according to one of the claims from 20 to 23, characterised inthat the interface (3) is provided with reading and/writing devices formemory movable supports.